A speaker is constructed as shown in FIG. 2.
A magnetic circuit 1 is composed of a lower plate 1a having a center pole section, a magnet 1b and an upper plate 1c. A frame 2 is mounted on the upper side of the magnetic circuit 1. An outer rim of the diaphragm 3 is connected to the inner rim of the frame 2, and the inner rim of the diaphragm 3 is connected to a voice coil bobbin 4 inserted into a magnetic gap 1d of the magnetic circuit 1.
The frame 2 has a lead out terminal 5. The voice coil bobbin 4 is wound up with a voice coil 6. The lead out terminal 5 is electrically connected to the voice coil 6 by the copper foil flexible wire 7.
As shown in FIG. 3, the copper foil flexible wire 7 is constituted of braiding or stranding a plurality of core wires 8, each of which is wound by copper foil 9. Although there are some other constitutions of the flexible wire, it is generally called a gold wire or glorious wire.
The speaker generates sounds by inputting sound signals to the lead out terminal 5 in order to drive the voice coil bobbin 4 and thus to vibrate the diaphragm 3.
Recently in a tendency to increase the input capacity to a speaker, there have been disadvantages when using the copper foil flexible wire 7. It vibrates by the vibration of diaphragm 3, which is called a hopping phenomenon. This phenomenon results, in noise being generated when the copper foil flexible wire 7 collides with diaphragm 3. The copper foil of the flexible wire 7 may break in an extreme case.
In order to overcome these disadvantages, some types of copper foil flexible wire 7 are impregnated with wax. However, this type of flexible wire 7 must be flame resistant against the rise of temperature itself, when the input capacity to the speaker is increased.
It is an object of the present invention to provide wax which is excellent as a surface treating agent, a copper foil flexible wire treated to be flame resistant, and a speaker using this flexible wire.